A portion of the human population has some malformation of the nasal passages which interferes with breathing, including deviated septa and swelling due to allergic reactions. A portion of the interior nasal passage wall may draw in during inhalation to substantially block the flow of air. Blockage of the nasal passages as a result of malformation, symptoms of the common cold or seasonal allergies are particularly uncomfortable at night, and can lead to sleep disturbances, irregularities and general discomfort.
Spring-based devices for dilating outer wall tissues of the human nose adjacent the nasal passages, and the use of resilient means to engage and urge outwardly the nasal passage outer walls from either the interior mucosa or exterior epidermis sides thereof, have a history spanning over one hundred years. Some examples of present external nasal dilators are disclosed in U.S. Pat. Nos. 6,453,901; D379,513; D429,332; D430,295; D432,652; D434,146; D437,64; U.S. patent application Ser. Nos. 08/855,103; 12/024,763; 12/106,289; and Japanese patent Reg. No. 1037944; the entire disclosures of which are incorporated by reference herein. The commercial success of at least one of these inventions, together with that of other modern external nasal dilators, collectively and commonly referred to as nasal strips, has led to the establishment of a nasal dilator product category in the consumer retail marketplace. Commercial success of prior art nasal dilator devices disclosed before 1990, in particular that of U.S. Pat. No. 1,292,083, and in the absence of evidence to the contrary, is presumed to be consistent with the consumer product environments at the times of those inventions.
A long-standing practice in the construction and use of medical devices which engage external bodily tissue (i.e., tissue dilators, nasal splints, ostomy devices, surgical drapes, etc.) is to interpose an interface material between the device and the user's skin to facilitate engagement of the device to the skin and to aid user comfort. Said material, such as a spunlaced polyester nonwoven fabric, typically has properties which permit limited, primarily plastic and somewhat elastic deformation within the thickness thereof. These properties can spread out peeling, separating or delaminating forces such as may be caused by: gravity acting on the weight of the device; the device's own spring biasing force or rigidity (such as that of a tissue dilator or nasal splint); biasing force that may be present in bodily tissue engaged by the device; surface configuration differences between the device and the skin of the device wearer; displacement of the device relative to the skin or external tissue as a result of shear, tensile, cleavage and/or peel forces imparted thereat via wearer movement (e.g., facial gestures) and/or contact with an object (e.g., clothing, pillow, bedding, etc.) that may cause partial or premature detachment of the device from the wearer. By spreading out these delaminating forces, said interface material acts as a buffering agent to prevent the transfer of said forces to its adhesive substance, if any, and thereby to the skin. Preventing the transfer of focused delaminating forces substantially eliminates any itching sensation (caused by the separation of the adhesive substance or device from the skin) that a wearer may experience if these delaminating forces were otherwise imparted directly to the skin.
External nasal dilators typically feature a functional element and an engagement element. The functional element consists of a metal or plastic member capable of resilient deformation such that when flexed it returns substantially to its initial, un-flexed, state. The engagement element typically consists of a flexible material with a pressure sensitive adhesive disposed on one side. Said material may further act as an interface buffer as described above. Adhesive may be used on the functional element to provide additional engagement means. The known nasal dilator art combines functional and engagement elements in a variety of configurations.
There has been a continuing need in the art to develop nasal dilators which address certain inherent limitations of the functional and engagement elements. These limitations include limited skin surface area adjacent the nasal passages, adhesive engagement vs. delaminating spring biasing forces, device comfort and durational longevity, and economical fabrication and assembly of dilator components.
Firstly, tissues associated with and adjacent the nasal passages have limited skin surface areas to which dilation may be applied. Said surfaces extend upward from the nostril opening to the cartilage just above the nasal valve, and extend outward from the bridge of the nose to each approximate line where the sides of the nose meet each cheek.
Secondly, nasal dilators are, of necessity, releasably engaged to outer wall tissues by use of pressure sensitive adhesives. Skin surfaces transmit moisture vapor to the surrounding atmosphere. The adhesives break down in the presence of skin oils, moisture and the transmission of moisture vapor, often within hours.
Thirdly, the functional element of modern nasal dilators is a flat, semi-rigid resilient member that is substantially rectangular or slightly arcuate in shape and made of thermoplastic resin. The resilient member is flexed across the bridge of the nose, extending over the nasal passages on each side of the bridge. When held thereto by the engagement element, the resilient member exerts a spring biasing force as it tries to return to its original, typically planar, state. The spring biasing force extends outward from the central portion of the device to the opposite end regions thereof, creating primarily peel forces at said end regions together with some tensile forces, which act to disengage the device from the skin surfaces.
To accommodate the average human nose, overall nasal dilator dimensions are typically from about 5.0 cm to 7.5 cm (2.0″ to 3.0″) in length and about 1.2 cm to 2.5 cm (0.5″ to 1.0″) in width. To produce from about 15 grams to about 30 grams of spring biasing force (enough to provide dilation or stabilization to nasal outer wall tissues without readily compromising the integrity of the engagement element), spring-based dilator device resilient members have dimensions from about 4.0 cm to about 6.0 cm (1.6″ to 2.4″) in length, and from about 0.61 cm to about 1.22 cm (0.24″ to 0.48″) in width, at a thickness of 0.18 mm or 0.25 mm (0.007″ or 0.010″). A resilient member thickness other than 0.010″ or 0.007″ is not preferred in the art, but could be incorporated into device design with proportionate adjustments to width and length.
A portion of known nasal dilator art is suitable or adaptable for commercialization in the present consumer retail markets. Some of these have had commercial success, including devices disclosed in U.S. Pat. Nos. D379,513; 6,453,901; 5,533,503; 5,546,929; RE35408; 7,114,495 and certain devices based upon Spanish Utility Model 289-561 for Orthopaedic Adhesive. While these devices provide sufficient dilation of nasal passageway tissue and thus provide the claimed benefit to the vast majority of users, they are not configured to fully overcome the aforementioned limitations.
The functional and engagement elements of modern nasal dilator devices are manufactured without regard to integrating them efficiently. Based on approximate dimensions of 2.63″L×0.63″W (from typical overall dimensions stated above), commercially available nasal strip devices that are substantially rectangular in shape typically use about 1.66 square inches of material for the interface/engagement material layer, and up to about 3.31 square inches of material if both an interface layer and a cover material layer are used. The use of both layers has been a best practice. Nasal strips are typically manufactured in a continuous process, oriented parallel to the machine direction (MD) of the material used. Standard manufacturing (converting) technique typically spaces one device from another by about 0.125″ on each side so that waste material can be removed as a single matrix. If finished dilators are to be individually packaged in the same operation, said spacing may be increased to about 0.19″, or more, on all sides. This extra spacing provides a suitable contact perimeter extending around each dilator unit so that upper and lower packaging material webs may form an adequate seal to each other. Individual packaging is also considered a best practice for nasal strips available in the present retail market.
Nasal strips fabricated in closer proximity to each other, in order to reduce material waste, for example, are typically packaged individually in a separate operation. Of course a separate packaging operation has a corresponding additional cost. Dilator manufacturers typically weigh the cost of wasted material against the cost of a separate packaging operation.
Material waste from manufacturing dilator devices, excluding material for the engagement element, may approach that which is devoted to the dilator itself. For example, dilator devices fabricated (converted) in a spaced-apart relationship using about 1.66 square inches of material for each of two layers (engagement layer and cover layer, as described above) requires about 6.0″ sq. of material total (2.63″ dilator length plus 0.19″ on each long side, multiplied by 0.63″ dilator width plus 0.19″ on each short side). Accordingly, 2×1.66″ sq. devoted to the device itself out of 6″ sq. of material is a usage-to-waste ratio of about 6:5, or about 55% material used to about 45% material wasted.
The usage-to-waste ratio of material used for the engagement element in dilator devices can range from as low as about 30%/70% to as high as about 67%/33% (where about 30% and 67% of the material, respectively, is devoted to the element itself) depending upon the dilator manufacturing technique used. Resilient members are typically formed from a continuous strip of material oriented parallel to the machine direction of the fabrication process. If the material strip is equal to the width of the finished resilient member, and the member extends to the lateral end edges of the finished dilator unit, there is a usage-to-waste ratio of about 2:1 (about 2″ resilient member length plus spacing between successive lengthwise dilators equals about 3″ total length). In this manner material waste is limited largely to the distance between successive dilator units fabricated lengthwise, end to end.
Dilator devices in which the resilient member is centered within the peripheral edges of the dilator (an “island placement” converting technique commonly used to simultaneously die cut and centrally register a component within the perimeter edges of a finished unit) may have as little as 30% of the material devoted to the resilient member element itself. In addition to the wasted material between successive dilator units fabricated lengthwise end to end, island placement typically requires an additional 0.125″ of material width on each long side of the finished resilient member, so as to remove waste material as a single matrix from around successive spaced apart resilient members. While the finished resilient member width is 2″ length×0.21″ width, adding 0.125″ of extra width on each long edge increases total width of resilient material strip to 0.46″. Thus 1.38″ sq. (3″×0.46″) of resilient element material is used to fabricate and position a 0.42″ sq. (2″×0.21″) resilient member; a usage-to-waste ratio of about 1:2.
It should be noted that the material waste described above does not include that from machine set-up and calibrating, or that from the pre-converting of materials as supplied by their respective manufacturers. However, even minor efficiencies can provide a competitive advantage and improve dilator manufacturers' value propositions in a consumer product retail environment. Based on the dimensions of dilator engagement and functional elements as described above, the embodiments of the present invention are conducive to material usage/waste of about 80%/20% or better for the resilient and base layer materials (about a 4:1 ratio), and about 75%/25% for the cover layer material (about a 3:1 ratio).
Nasal dilator devices heretofore available in the consumer marketplace feature a symmetric resilient member or members. That is, each horizontal half of each member (extending onto opposing nasal outer wall tissues) is the mirror image of the other. Where there are two resilient members disclosed in the prior art, each member is fabricated to identical or similar dimensions. Uniform resilient members are generally more economical to mass produce. The present invention illustrates that non-identical and asymmetric resilient members may be fabricated with equal or greater efficiency as their symmetric counterparts, at the same or lower cost.
U.S. Pat. No. 6,453,901 discloses a manufacturing method of forming a strip of identical web-connected resilient members from an elongated material sheet, laminating the strip to strips of base layer and cover layer material, and die cutting the laminate on predetermined lines to form successive nasal dilators with their lengths oriented perpendicular to the machine direction of the fabrication process. Material between the web-connected resilient members and finished dilators is wasted. Accordingly, the '901 disclosure does not teach this technique as a manufacturing efficiency, but rather as an alternative process to the traditional lengthwise, end-to-end, fabrication methods described above, and further as a means to form complex resilient member structures. The present invention builds upon the '901 disclosure by illustrating methods whereby to form complex resilient member structures while limiting waste material and improving manufacturing efficiency.
In the modern consumer product market, nasal dilator innovation and competitive value propositions to resellers and consumers have been limited. Accordingly, there is a need in the art for both nasal dilator innovation and premium quality dilator devices at lower costs. The present invention is directed to discrete embodiments and various forms of external nasal dilators, including techniques and methods for manufacturing finished dilator units and their constituent elements, members and components.